This invention relates to a new and improved process and apparatus for heating a steel bath charged with large quantities of scrap.
Currently, various processes are well known to those skilled in the art wherein energy required for melting large quantities of scrap is only partially derived from external sources. The necessary energy requirements have been provided by the use of excess internal energy and is most easily obtained when gas or plasma burners or induction or resistance radiators are used. For example, in his U.S. Pat. Nos. 4,349,382; 4,325,730 and 4,345,746, applicant has described how the use of liberated heat derived from afterburning carbon monoxide (CO) during decarburization of steel baths in order to melt larger quantities of scrap has been efficiently utilized. Also, in his Luxembourg Patent LU 83,814, applicant discloses how additional energy capacity may be obtained for a steel bath through selective carburization by an external source.
Despite the successes of the above identified energy efficient processes, problems remain for the steelmaking industry in attempting to utilize converter waste gases in applications other than as a fuel gas to preheat scrap. In particular, a process and apparatus which would permit a steel bath charged with large quantities of scrap to be heated during refining so that the energy present in uncombusted converter waste gases would be efficiently consumed would be extremely useful. A process as described would economically avoid or reduce the use of external energy sources.